Comparing Mark IV Mode to a IIC+

Just curious. I see a lot of people comparing the IIC+ mode to a real IIC+ and the Mark IV mode to a real Mark IV, but has anyone compared the Mark IV mode to a real IIC+? Since the design of the channel is supposed to be based on the IIC+ regardless of mode and the Mark IV mode is using the larger filter cap used on the IIC+ with a graphic EQ, would that be closer to what everyone expects from that mode?

Funny enough, this was posted here a few weeks ago... a video which compares exactly what you're inquiring about:

https://www.youtube.com/watch?v=VO-1jVVCLMQ

Honestly, I've tried this Mark IV mode with "unusual" EQ setting and I really am digging it.

Thanks! That's what I was looking to see. Since I haven't been playing live, I've been messing with the settings and learning more about the amp, and it seems to make sense that the Mark IV mode may be closer to what someone would expect the IIC+ mode to sound like based on what I've read in the manual.

I have never owned a Mark IV.

Having said that, I think that you can expect Mark IV mode to sound a lot like a IIC+ that has a graphic eq and PULL DEEP engaged. Especially if you switch it ever to Triode mode. I'm not aware of how much the preamp's lead channel evolved from IIC+ to the IV. Obviously a lot of other stuff iterated over time, I'm just talking about the core lead preamp circuit itself.

I tend to think of IIC+ mode as Tight and IV mode as Deep.

I even have a No-EQ IIC+ and I don't think IIC+ mode sounds like it. IV mode is close"er", but IV mode (like a IV) lacks the nasally mid hump that IIC+ have.

When trying to recreate a IIC+"esque" feel, I actually like Crunch mode with a modest boost the best. It's a little heavy handed on the bottom end in comparison, but it has IMO the most organic gain structure on the amp.

Came across this video last night.. Had been close to ordering some AT7s to reduce the harshness based on a few other threads. May still do, but will play around more first.

These settings really smooth out the amp for me. I had been running mids higher for more grind, but treble not as high. After having more recent experience with older Marks I better understand the treble will bring in more gain and matching the treble sweet spot with the gain sweet spot is important. Though Mark V mid control is a bit more powerful than the other Marks (to my ears).

Biggest learning was really the impact of an extremely low setting of the 6600 fader. Hard to get the GEQ V mentality out of my head. Very different GEQ than the other Marks (that I have).

MarkIV-A or MarkIV-B ? it's seems the A is more close to MkIIC+ 8)

If you dig into the schematic, all three modes are Mark IIC+ circuits.

In Mark IIC+ mode it has the small coupling cap of non-GEQ models, and PULL DEEP is disengaged.

In Mark IV mode, it has the larger coupling cap of GEQ models and PULL DEEP is engaged. And in fact, the Mark IV didn't even have a PULL DEEP circuit that matches, so it's not even an exact Mark IV recreation, but it IS a IIC+ recreation.

EXTREME just changes the negative feedback in a way that didn't exist before.

So honestly, I think people just compare to the one on the label because they chose to label it like that and haven't dug in to realize they're both IIC+ modes. Honestly they should have called it Tight, Deep, Extreme.

But they wanted to market the IIC+ legacy. But if they called it IIC+ tight, IIC+ deep, extreme, then someone would go "but I like my mark IV, what if I can't get my sound". But you're right, I think more people should be compariing the Mark IV mode because if you're into heavier tones it was probably a GEQ model and PULL DEEP engaged. And the manual could have used a "for comparing to IIC+ with GEQ use Mark IV mode and do this" section to go beside the one for the IIC+ mode.